Google has privately invested in a firm developing a very different and potentially rival quantum computer technology.

Google, a major figure in quantum computer development using superconducting technology to produce quantum bits (qubits), has invested a multi-million dollar sum into a firm developing an entirely different quantum technology: neutral atoms.

In mid-October 2024 – five years after Google announced it had achieved ‘quantum supremacy’ in 2019 – it invested in the quantum hardware firm QuEra Computing. This was a private investment in a private firm that was founded in 2018. The investment is outside of venture funding, and there are no disclosed details.

“This investment from Google Quantum AI, coupled with an additional financing initiative to be announced in the coming weeks, allows us to execute on our vision and company strategy, and positions us as the recognized market leader for neutral atom-based quantum computing solutions,” said Andy Ory, Interim Chief Executive Officer of QuEra.

Despite the lack of detail, we can confidently assume that this is at least a double-digit million dollar investment in a firm developing a different quantum technology to that used by Google when it achieved quantum supremacy five years ago. In this sense, QuEra could be considered a competitor to Google – which raises a simple question: why invest in a competitor? 

Without explicit details from either side, we can only conjecture. But it is an important question for cybersecurity. The sooner a quantum computer with sufficient computing power to run Shor’s algorithm – or any one of its fine-tuned derivatives – is produced, the greater the threat to all current public key encrypted data – and in many ways the integrity of the internet itself. Enterprises are already struggling to implement NIST’s PQC algorithms without knowing how much time they have available.

Of course, the race for large-scale working quantum goes way beyond running Shor’s algorithm – the power of quantum will have huge societal benefits in new medicines, new materials, improved solar cells, better understanding of natural processes such as climate change, and so much more. The threat to current security is just an unhappy by-product; but it’s what concerns us here.

Google’s own quantum development is focused on superconducting qubits. This is possibly the most popular approach – IBM also uses superconducting technology. QuEra’s approach is very different. It uses neutral atom qubits. Understanding the differences between these two modalities could help us understand Google’s investment, and whether neutral atoms bring the ‘cryptopocalypse’ any closer.

Manufacturing qubits via superconductivity requires reducing temperatures to near zero. Since there is a manufacturing element, there is a possibility of minor variations in the qubits produced. The qubits themselves are fragile and susceptible to electromagnetic interference and decoherence. The computing power of quantum increases with the number of usable qubits, with a large but variable (depending on the precise technology being used) number of additional qubits required solely for correcting the errors introduced by their fragility or instability. The concept of coherence is important. This indicates the length of time a qubit can retain its quantum state before decoherence and collapsing into a classical two-state bit. 

Quantum computing provides ‘probable’ responses rather than the deterministic responses of classical computing. The elimination of errors and elongation of coherence during computation are essential to make the probable responses probably correct. 

Superconducting qubits also require complex wiring and cryogenic cooling and are largely fixed in position. There are no known laws of physics that would prevent our current understanding of quantum behavior from doing what we expect – but the engineering difficulties in building a large scale reliable superconducting quantum computer are immense, and increase with any increase in the number of qubits harnessed.

Neutral atom qubits operate and are used very differently. Key elements include much greater scalability, and a much smaller footprint than that required for a superconducting quantum computer. One neutral atom equals one qubit with no variation between them. The individual atoms are packed tightly together and are held in position by focused beams of laser light, known as optical tweezers, and then ‘operated’ by laser or other electromagnetic signals. 

This offers many theoretical advantages over building large scale superconducting devices. Since they are neutral atoms, the qubit itself is not susceptible to electromagnetic interference. They don’t need special cooling and can be packed tightly together, reducing the footprint of the device. Since they are held in place by the optical tweezers, large arrays can be created and rearranged with relative ease. This is important for executing complex quantum algorithms. 

They also have a naturally long coherence time, further reducing the likelihood of errors. This doesn’t mean that neutral atom quantum computers don’t require error correction, but those errors will likely have a different cause – for example a 3D array of atoms held in place by optical tweezers will be more susceptible to external vibrations.

So, what we have is a global race by multiple major companies to develop large scale quantum computers, using different quantum technologies (or modalities), which will in the process disrupt our current methods of maintaining the confidentiality and integrity of sensitive data. As security practitioners, our concern is primarily over how soon this disruption of current cryptographic algorithms (known as the cryptopocalypse) will occur, and whether we have time to implement NIST’s quantum safe algorithms and future crypto agility before it happens.

Can Google’s investment in a rival modality tell us anything about the date of the cryptopocalypse? It cannot. We don’t know why Google has done this. It could be that Google is simply hedging its bets. On paper, it is not unlikely that the neutral atom modality will create a large quantum computer before superconducting can do the same. But we don’t know for certain.

It could be that Google is positioning itself for greater collaboration into some of the ongoing quantum problems, such as error correction. Both Google, with its own mammoth resources, and QuEra, in collaboration with Harvard, have strong research into error correction.

It could be that Google is covering bases in case it turns out that neutral atom quantum is better at solving some types of problems while superconducting quantum is better at others.

While we don’t know why Google has invested in possibly the primary neutral atom company – QuEra Computing – and nor do we have any clearer view of when a cryptanalysis-relevant quantum computer will become available, it does demonstrate that quantum manufacturers are constantly exploring ways to make that sooner rather than later.

It is important that CISOs monitor these developments lest they get caught short in implementing NIST’s PQC algorithms before PKE becomes irrelevant.

Related: Post-Quantum Cryptography Standards Officially Announced by NIST – a History and Explanation

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Related: Quantum Computing’s Threat to Public-key Cryptosystems

Related: IBM Delivers Roadmap for Transition to Quantum-safe Cryptography